Total refactoring performed

server/db.ts

@@ -0,0 +1,24 @@
+import Database from 'better-sqlite3';
+
+const db = new Database('session_state.db');
+
+// Initialize tables
+db.exec(`
+  CREATE TABLE IF NOT EXISTS sessions (
+    id TEXT PRIMARY KEY,
+    state TEXT NOT NULL,
+    updated_at DATETIME DEFAULT CURRENT_TIMESTAMP
+  )
+`);
+
+const getSessionStmt = db.prepare('SELECT state FROM sessions WHERE id = ?');
+const upsertSessionStmt = db.prepare('INSERT INTO sessions (id, state) VALUES (?, ?) ON CONFLICT(id) DO UPDATE SET state = excluded.state, updated_at = CURRENT_TIMESTAMP');
+
+export function getPersistedSession(id: string) {
+    const row = getSessionStmt.get(id) as { state: string } | undefined;
+    return row ? JSON.parse(row.state) : null;
+}
+
+export function persistSession(id: string, state: any) {
+    upsertSessionStmt.run(id, JSON.stringify(state));
+}

server/index.ts

@@ -0,0 +1,103 @@
+import express from 'express';
+import path from 'path';
+import http from 'http';
+import { WebSocketServer, WebSocket } from 'ws';
+import { v4 as uuidv4 } from 'uuid';
+import { defaultState } from '../src/defaultState.js';
+import { getPersistedSession, persistSession } from './db.js';
+
+import { fileURLToPath } from 'url';
+import { dirname } from 'path';
+
+const __filename = fileURLToPath(import.meta.url);
+const __dirname = dirname(__filename);
+
+const app = express();
+const port = process.env.PORT || 3001;
+const subfolder = '/ag-beats';
+const distPath = path.join(__dirname, '../dist');
+
+const COLORS = ['#F94144', '#F3722C', '#F8961E', '#F9C74F', '#90BE6D', '#43AA8B', '#4D908E', '#577590', '#277DA1'];
+const getRandomColor = () => COLORS[Math.floor(Math.random() * COLORS.length)];
+
+app.use(subfolder, express.static(distPath));
+app.get(subfolder + '/*', (req, res) => res.sendFile(path.join(distPath, 'index.html')));
+app.get('/', (req, res) => res.redirect(subfolder));
+
+const httpServer = http.createServer(app);
+const wss = new WebSocketServer({ path: '/ag-beats', server: httpServer });
+
+interface ClientInfo {
+    ws: WebSocket;
+    color: string;
+}
+
+interface Session {
+    clients: Map<string, ClientInfo>;
+    state: any;
+}
+
+const sessions = new Map<string, Session>();
+
+wss.on('connection', (ws: WebSocket, req) => {
+    const url = new URL(req.url || '', `http://${req.headers.host}`);
+    const sessionId = url.searchParams.get('sessionId');
+    const clientId = uuidv4();
+    const clientColor = getRandomColor();
+
+    if (!sessionId) return ws.close(1008, 'Session ID required');
+
+    if (!sessions.has(sessionId)) {
+        const persisted = getPersistedSession(sessionId);
+        const initialState = persisted || JSON.parse(JSON.stringify(defaultState));
+        sessions.set(sessionId, { clients: new Map(), state: initialState });
+    }
+
+    const session = sessions.get(sessionId)!;
+    session.clients.set(clientId, { ws, color: clientColor });
+
+    console.log(`Client ${clientId} connected to session ${sessionId}`);
+
+    ws.send(JSON.stringify({ type: 'welcome', payload: { clientId } }));
+
+    const broadcastUserUpdate = () => {
+        const userList = Array.from(session.clients.entries()).map(([id, { color }]) => ({ id, color }));
+        const msg = JSON.stringify({ type: 'user-update', payload: { users: userList } });
+        session.clients.forEach(({ ws: c }) => c.readyState === WebSocket.OPEN && c.send(msg));
+    };
+
+    broadcastUserUpdate();
+
+    ws.on('message', (messageBuffer) => {
+        const message = JSON.parse(messageBuffer.toString());
+
+        if (message.type === 'get_state') {
+            ws.send(JSON.stringify({ type: 'session_state', payload: session.state }));
+            return;
+        }
+
+        const messageToSend = JSON.stringify({ ...message, senderId: clientId });
+
+        if (message.type !== 'cursor-move') {
+            session.state = { ...session.state, ...message.payload };
+            persistSession(sessionId, session.state);
+        }
+
+        session.clients.forEach(({ ws: c }) => {
+            if (c.readyState === WebSocket.OPEN) c.send(messageToSend);
+        });
+    });
+
+    ws.on('close', () => {
+        console.log(`Client ${clientId} disconnected from session ${sessionId}`);
+        session.clients.delete(clientId);
+        if (session.clients.size === 0) {
+            // keep session in DB but remove from memory
+            sessions.delete(sessionId);
+        } else {
+            broadcastUserUpdate();
+        }
+    });
+});
+
+httpServer.listen(port, () => console.log(`AG Beats (TS) started on port ${port}`));